> I actually thought something like the CLOCK_MONOTONIC or CLOCK_BOOTTIME were > used for providing uptime to the user, but those do not allow date changes.
You are assuming a certain implementation, and then thinking what properties the program "must" have. Try thinking the other way around: What properties the program should have, and then filter out the implementations that don't satisfy these properties. > I do not understand the relationship between date and boottime. Might make > sense for VM's, but for non-VM's I do not get it. We did the changes - for year-2038 safety on Linux/{x86,arm}, - so that it is stable across 'sudo date MMDDhhmm' invocations [2], - so that it doesn't display a fantasy time in VMs [1]. Even if it were only for VMs. VMs are the basis of cloud environments, and are thus pretty important nowadays. Bruno [1] https://lists.gnu.org/archive/html/bug-gnulib/2023-08/msg00064.html [2] https://lists.gnu.org/archive/html/bug-gnulib/2023-08/msg00067.html